at automobile traveling at 30 mph hits a stone wall. from what height would the car have to fall to acquire the same velocity (1mph = 0.45 m/s)

Question

at automobile traveling at 30 mph hits a stone wall. from what height would the car have to fall to acquire the same velocity (1mph = 0.45 m/s)

Answer 1

You know its speed v must be 30 mph.  (The part about colliding with a wall is irrelevant.)  It must fall from a height h such that 

 

mgh = mv²/2 ⇒

 

h = v²/(2g)

 

You know g.  Convert v to m/s, plug it into this equitation, and get h in meters.